Food tray and matable lid

ABSTRACT

A container configured to contain food stuffs. The container includes a food tray and a matable lid. The food tray includes a tapered portion connected to an upper lip having an upper lip edge perimeter. The matable lid includes a mating portion including an inwardly tapered portion and an outwardly tapered portion forming an undercut region having an undercut region perimeter. The undercut region perimeter is less than the upper lip edge perimeter such that the undercut region flexes when a force is exerted on the matable lid during mating with the food tray. This permits the upper lip to overcome the undercut region and be held in place in a recess in the mating portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application Ser. No. 62/725,426 filed Aug. 31, 2018, the disclosure of which is hereby incorporated in its entirety by reference herein.

TECHNICAL FIELD

The disclosure relates a food tray and matable lid.

BACKGROUND

Paperboard trays have been developed to contain and support food stuffs. These trays may be covered by a lid to protect the food stuffs from debris and/or to reduce spilling of the food stuffs contained in the tray. The lid is typically made of a transparent plastic material. The interface between the lid and tray is not optimal when the lid simply sits on top of the tray. Improvements in the design of the interface between the lid and tray would be beneficial.

SUMMARY

In one embodiment, a container configured to contain food stuffs is disclosed. The container includes a food tray and a matable lid. The food tray includes a tapered portion connected to an upper lip having an upper lip edge perimeter. The matable lid includes a mating portion including an inwardly tapered portion and an outwardly tapered portion forming an undercut region having an undercut region perimeter. The undercut region perimeter is less than the upper lip edge perimeter such that the undercut region flexes when a force is exerted on the matable lid during mating with the food tray. This permits the upper lip to overcome the undercut region and be held in place in a recess in the mating portion.

In another embodiment, a container configured to contain food stuffs is disclosed. The container includes a food tray and a matable lid. The food tray includes a tapered portion connected to an upper lip having an upper lip edge perimeter. The food tray includes a paperboard layer. The matable lid includes a mating portion including an inwardly tapered portion and an outwardly tapered portion forming an undercut region having an undercut region perimeter. The matable lid is formed of a plastic material. The undercut region perimeter is less than the upper lip edge perimeter such that the undercut region flexes when a force is exerted on the matable lid during mating with the food tray. This permits the upper lip to overcome the undercut region and be held in place in a recess in the mating portion.

In yet another embodiment, a container configured to contain food stuffs is disclosed. The container includes a food tray and a matable lid. The food tray includes a tapered portion connected to an upper lip. The matable lid includes a mating portion including an inwardly tapered portion and an outwardly tapered portion forming an undercut region. The taper angle of the inwardly tapered portion is less than the taper angle of the outwardly tapered portion and the peripheral width of the inwardly tapered portion is less than the peripheral width of the outwardly tapered portion such that the undercut region flexes when a force is exerted on the matable lid during mating with the food tray. This permits the upper lip to overcome the undercut region and be held in place in a recess in the mating portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a perspective view of a lid mated to a tray according to an embodiment.

FIG. 2 depicts a top view of the lid mated to the tray depicted in FIG. 1.

FIG. 3 depicts a side view of the lid mated to the tray depicted in FIG. 1.

FIG. 4 depicts a cross-section view of the lid of FIG. 1 unmated to the tray of FIG. 1 taken along line 4-4 of FIG. 3.

FIG. 5 depicts a cross-section view of the lid of FIG. 1 mated to the tray of FIG. 1 taken along line 4-4 of FIG. 3.

FIG. 6 depicts a partial, cross-section view of the mating interface of the lid and tray of FIG. 1 taken along 4-4 of FIG. 3.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

Conventional lids for paperboard food trays do not create an adequate mating interface for some applications. Certain lids simply sit atop the paperboard tray. These lids do not support one or more of the side walls of the paperboard tray. Certain lids do not fit a wide array of size variations of paperboard food trays. This is a significant issue since in certain applications the industry wide variation in the outer perimeter of the food tray may be up to 3/32″. Also, paperboard food trays are often treated with a resin coating on the inner surface of the food tray. This resin coating helps protect the paperboard from deterioration from the food stuffs contained in the tray. The coating also gives the inner surface of the food tray a glossy or shiny appearance. However, during the baking or cooking process, the tray may shrink under certain heat, dwell time and pressure conditions. This shrinkage increases the chances that that the lid may not fit on the food tray post baking or cooking. One or more embodiments set forth herein address one or more of the problems set forth above.

FIG. 1 depicts a perspective view of lid 10 releasably mated to tray 12. Tray 12 may be constructed of a paperboard layer. Paperboard is a fibrous material that can come from fresh, virgin sources, such as, wood, or from recycled waste paper. Virgin paper may be made from a high content of wood pulp, for example, 90% wood pulp. The thickness of the paperboard layer may be any of the following values or within a range of any two of the following values: 0.006 inches, 0.012 inches, 0.018 inches, and 0.024 inches.

Tray 12 has an inner surface 14 and an outer surface 16. Inner surface 14 of tray 12 may be coated with a polyethylene (PE) resin. Outer surface 16 may be uncoated. Tray 12 may be sized to contain food stuffs, such as, but not limited to, pizza, lasagna, breadsticks, or pretzels. In such embodiments, the materials used to construct the tray are food grade materials. The thickness of the coating layer may be any of the following values or within a range of any two of the following values: 0.003 inches, 0.004 inches, 0.005 inches, and 0.006 inches.

Lid 10 may be constructed of a transparent, semi-transparent, or opaque plastic material, and in some embodiments, a food grade plastic material. Non-limiting examples of food grade plastic material include polystyrene (PS), high density polyethylene (HDPE), and polyethylene terephthalate.

As shown in FIGS. 3, 4 and/or 5, tray 12 is formed of a base portion 18, a peripheral portion 20, and an upper lip 22. Base portion 18 is bounded at a base portion periphery 24 by lower edge 26 of peripheral portion 20. As shown in FIG. 2, Base portion 18 includes edges 28 and corners 30. As shown in FIGS. 4 and 5, base portion 18 also includes a peripheral channel 32 extending away from inner surface 14 of tray 12. Peripheral channel 32 is configured to add strength to base portion 18 and more generally tray 12 to support food stuffs contained within tray 12. As shown in FIG. 2, edges 28 of base portion 18 are generally linear and curve upward toward peripheral portion 20, and corners 30 of base portion 18 are radiused. In one or more embodiments, generally linear means that the dimension does not deviate from a linear relationship by more than ±5%.

As shown in FIGS. 4 and 5, peripheral portion 20 includes an upper edge 34 in addition to lower edge 26. Peripheral portion 20 includes a lower tapered portion 36 and an upper tapered portion 38, separated by an extending portion 40 extending away from base portion 18. In another embodiment, the peripheral portion does not include an extending portion and includes a continuous tapered portion.

Extending portion 40 is generally parallel or parallel to base portion 18. Lower and upper tapered portions 36 and 38 taper outward from lower edge 26 toward upper edge 34 relative to base portion 18 by a lower and upper taper angle, respectively. In certain embodiments, the lower and upper taper angles are the same, and in other embodiments, the lower and upper taper angles are different. As shown in FIGS. 4 and 5, the upper and lower taper angles are the same. The upper and lower taper angles, selected independent of each other, may be any of the following values or in the range of any of the following two values: 20 degrees, 22 degrees, 24 degrees, 26 degrees, 28 degrees or 30 degrees. Upper tapered portion 38 is offset by the width of extending portion 40, as shown in FIGS. 4 and 5. The offset may be any of the following values or in the range of any of the following two values: 0.05 inches, 0.1 inches, 0.15 inches, and 0.2 inches. The width of upper tapered portion 38 may be any of the following values or in the range of any of the following two values: 0.2 inches, 0.25 inches, 0.3 inches, and 0.35 inches. The width of lower tapered portion 36 may be any of the following values or in the range of any of the following two values: 0.75 inches, 1.0 inches, 1.25 inches, and 1.5 inches. The ratio of the widths of the lower tapered portion 36 to the upper tapered portion 38 may be any of the following values or in the range of any of the following two values: 6:1, 5:1, 4:1 or 3:1. Extending portion 40 forms a shelf 42 on inner surface 14 of tray 12. Upper edge 34 of peripheral portion 20 is generally linear in regions that curve toward adjacent sides 46 of peripheral portion 20. Adjacent sides 46 are generally planar in shape. Upper tapered portion 38 and extending portion 40 are configured to reinforce and strengthen tray 12 by forming a ridge in this region of peripheral portion 20.

Tray 12 also includes upper lip 22, which extends outwardly from upper tapered portion 38. The width of upper lip 22 may be any of the following values or in the range of any two of the following values: 0.1 inches, 0.2 inches, 0.3 inches, and 0.4 inches. As shown in FIG. 1, corners 48 of upper lip 22 are radiused and edges 50 are generally linear.

Tray 12 may be formed from a pressing process in which a generally planar paperboard material is pressed into a final shape using a die. The planar paperboard material may be treated with a coating prior to pressing the material into the final shape. The pressing process may create areas with increased nominal thickness where the material gathers or bunches. Corners 30 of base portion 18, edges 28 of peripheral portion 20 and corners 48 of upper lip 22 may be regions in which the nominal thickness is increased due to gathering or bunching. This increase in thickness is configured to impart additional strength and reinforcement to tray 12.

As shown in FIGS. 3, 4 and/or 5, lid 10 includes upper portion 52, peripheral portion 54, mating portion 56 and lower lip portion 58. Upper portion 52 includes planar portion 60 extending towards and bounded by edges 62 and corners 64, as shown in FIG. 2. Edges 62 are generally linear and curve downward into peripheral portion 54. Corners 64 includes a number of ridges 66 and valleys 68 to provide additional reinforcement and strength to lid 10. As shown in FIG. 1, the number of ridges 66 and valleys 68 extend past edges 62 of upper portion 52.

Peripheral portion 54 is partially bounded on its upper side by edges 62. The number of ridges 66 and valleys 68 of upper portion 52 extend downwardly and correspondingly into a number of ridges and valleys 70 and 72 of peripheral portion 54, thereby forming the corners 74 of peripheral portion 54. Sides 75 extend between and are bounded by adjacent corners 74.

Lid 10 also includes mating portion 56. As shown in FIGS. 2 and 6, mating portion 56 has a base portion 76 that extends around the periphery of mating portion 56. The number of ridges and valleys 70 and 72 terminate into base portion 76. A number of alternating inwardly and outwardly chamfered portions 78 and 80 are situated between each corner 74 of peripheral portion 54 and a corresponding portion of base portion 76. Chamfered portions 78 and 80 are generally rectangular in shape. Inwardly chamfered portions 78 have a vertical surface that is recessed further away from the vertical surfaces of the outwardly chamfered portions 80. Inwardly and outwardly chamfered portions 78 and 80 may each have a width of any of the following values or in the range of any two of the following values: 0.1 inches, 0.15 inches, and 0.2 inches. Inwardly and outwardly chamfered portions 78 and 80 may each have a depth of any of the following values or in the range of any two of the following values: 0.1 inches, 0.15 inches, and 0.2 inches. The alternation of the inwardly and outwardly portions 78 and 80 are configured to add strength to lid 10.

Edges 82 of base portion 76 are generally linear and curved downward and corners 84 of base portion 76 are radiused. In one or more embodiments, the shapes of edges 82 and corners 84 of base portion 76 follow the shapes of edges and corners of upper lip 22 of tray 12. Mating portion 56 also includes a vertically extending portion 87 extending away from base portion 76 at its edges 82 and corners 84. Mating portion 56 also includes inwardly tapered portion 86 extending inward toward the center of lid 10 and outwardly tapered portion 88 extending outward away from the center of lid 10. Inwardly and outwardly tapered portions 86 and 88 are connected to each other through an undercut region 92. In one or more embodiments, the inwardly and outwardly tapered portions 86 and 88 and undercut region 92 extend the entire perimeter of lid 10.

In one embodiment, the peripheral width and taper angle of inwardly tapered portion 86 is selected so that undercut region 92 has a perimeter that is less than the perimeter of upper lip 22 of tray 12. Accordingly, when lid 10 is mated to tray 12, as shown in FIGS. 4 and 5, undercut region 92 contacts a portion of the peripheral edge of upper lip 22. This interference is overcome by applying force to lid 10 so that lid 10 flexes and/or upper lip 22 deforms, and undercut region 92 passes over the peripheral edge of upper lip 22, at which point, the peripheral edge of upper lip 22 is located at least partially within a recess 94 formed by inwardly and outwardly tapered portions 86 and 88 and undercut region 92. The applied force may “snap” the lid 10 into place over tray 12 with an associated audible “snapping” sound that will signal to the user that the placement of lid 10 over tray 12 is correct and the two are mated. In one embodiment, the width and taper angle of outwardly tapered portion 88 is selected so that the outer edge of outwardly tapered portion 88 is greater than the perimeter of upper lip 22 of tray 12. Accordingly, when lid 10 is mated to tray 12, as shown in FIGS. 4 and 5, the peripheral edge of upper lip 22 clears outwardly tapered portion 88 before contacting undercut region 92. The dimensional relationships set forth in this embodiment may be maintained around the entire periphery of the lid 10 and tray 12. In other embodiments, this relationship is maintained in certain discrete regions around the peripheries, such as in the corner regions.

As shown in FIG. 6, recess 94 has a width that may be any one of the following values or any range of any of the two following values: 0.040 inches, 0.045 inches, 0.5 inches, 0.055 inches, and 0.060 inches. As also shown in FIG. 6, the taper angle of the inwardly tapered portion 86 is less than the taper angle of the outwardly tapered portion 88. The peripheral width of inwardly tapered portion 86 is less than the peripheral width of the outwardly tapered portion. These dimensions permit the snapping configuration set forth above.

When peripheral edge of upper lip 22 is seated within recess 94, inwardly and outwardly chamfered portions 78 and 80 abut the inner surface of a portion of upper tapered portion 38 of peripheral portion 20 of tray 12. In the mated configuration, inwardly and outwardly chamfered portions 78 and 80 exert a holding force against this inner surface, thereby enhancing the strength of the interconnection of lid 10 and tray 12.

Planar portion 60 of lid 10 extends the periphery of lid 10 and includes tabs 96 at its corners. Tabs 96 are configured to be grasped by a user to release lid 10 from its mating configuration with tray 12.

Tray 12 may be an ovenable tray that can withstand high temperatures of an oven, such as 300° F., 350° F., 400° F., 450° F., 500° F., 550° F. or 600° F., or any temperature range formed from any two of these temperature values. Accordingly, the ovenable tray is configured to withstand a baking or cooking process at these temperatures for a recommended baking or cooking time, otherwise referred to as a dwell time, for food stuffs contained in tray 12. The dwell time may be any of the following values or within a range of any two of the following values: 15 minutes, 30 minutes, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 4 hours or 5 hours. After the dwell time elapses and tray 12 is removed from the oven, lid 10 may be mated to tray 12. Another variable associated with ovenable trays is the pressure of the oven. The pressure of the cooking vessel may be any of the following values or within a range of any two of the following values: 1 atm, 2 atm, 5 atm, and 10 atm.

The temperature, dwell time, and/or pressure may affect the dimensional stability of the ovenable tray. For instance, if the tray is coated with a resin, the resin may rehydrate during the cooking or baking process, and in so doing, shrink the overall dimensions of the ovenable tray. In some instances, the shrinkage may be 1/32″, 1/16″, or 3/32″. In one or more embodiments, lid 10 can accommodate this variation in size through recess 94 and flexing undercut region 92. These embodiments can also accommodate manufacturing size variations as well. While undercut region 92 can flex to accommodate different size variations (e.g., variations in the dimensions of the outer periphery of upper lip 22 of tray 12), alternating inwardly and outwardly chamfered portions 78 and 80 can exert a holding force on tray 12. In certain embodiments, this cooperation between these two structures provide a beneficial matable lid for paperboard trays.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention. 

What is claimed is:
 1. A container configured to contain food stuffs, the container comprising: a food tray including a tapered portion connected to an upper lip having an upper lip edge perimeter; and a matable lid including a mating portion including an inwardly tapered portion and an outwardly tapered portion forming an undercut region having an undercut region perimeter, the undercut region perimeter is less than the upper lip edge perimeter such that the undercut region flexes when a force is exerted on the matable lid during mating with the food tray, thereby permitting the upper lip to overcome the undercut region and be held in place in a recess in the mating portion.
 2. The container of claim 1, wherein the matable lid includes a peripheral portion having alternating inwardly and outwardly chamfered portions extending therefrom, the alternating inwardly and outwardly chamfered portions configured to hold the upper lip of the food tray in place with respect to the matable lid.
 3. The container of claim 1, wherein the upper lip extends outwardly from the tapered portion.
 4. The container of claim 1, wherein the undercut region extends an entire perimeter of the matable lid.
 5. The container of claim 1, wherein when the matable lid is being mated to the food tray, the undercut region is configured to contact a portion of a peripheral edge of the upper lip.
 6. The container of claim 1, wherein when the matable lid is mated to the food tray, a peripheral edge of the upper lip is located at least partially within a recess formed by the undercut region.
 7. A container configured to contain food stuffs, the container comprising: a food tray including a tapered portion connected to an upper lip having an upper lip edge perimeter, the food tray including a paperboard layer; and a matable lid including a mating portion including an inwardly tapered portion and an outwardly tapered portion forming an undercut region having an undercut region perimeter, the matable lid formed of a plastic material, and the undercut region perimeter is less than the upper lip edge perimeter such that the undercut region flexes when a force is exerted on the matable lid during mating with the food tray, thereby permitting the upper lip to overcome the undercut region and be held in place in a recess in the mating portion.
 8. The container of claim 7, wherein the paperboard layer includes an outer surface and an inner surface, the inner surface has an inner surface coating coated thereon.
 9. The container of claim 8, wherein the inner surface coating includes a polyethylene (PE) resin.
 10. The container of claim 8, wherein the outer surface is uncoated.
 11. The container of claim 7, wherein the plastic material is a transparent, semi-transparent or opaque plastic material.
 12. The container of claim 7, wherein the plastic material is polystyrene (PS), high density polyethylene (HDPE), and polyethylene terephthalate.
 13. A container configured to contain food stuffs, the container comprising: a food tray including a tapered portion connected to an upper lip; and a matable lid including a mating portion including an inwardly tapered portion and an outwardly tapered portion forming an undercut region, a first taper angle of the inwardly tapered portion is less than a second taper angle of the outwardly tapered portion and a first peripheral width of the inwardly tapered portion is less than a second peripheral width of the outwardly tapered portion such that the undercut region flexes when a force is exerted on the matable lid during mating with the food tray, thereby permitting the upper lip to overcome the undercut region and be held in place in a recess in the mating portion.
 14. The container of claim 13, wherein the matable lid includes a peripheral portion having alternating inwardly and outwardly chamfered portions extending therefrom, the alternating inwardly and outwardly chamfered portions configured to hold the upper lip of the food tray in place with respect to the matable lid.
 15. The container of claim 14, wherein when the upper lip is seated within the recess, alternating inwardly and outwardly chamfered portions abut an inner surface of a portion of the tapered portion.
 16. The container of claim 13, wherein the tapered portion includes an upper tapered portion and a lower tapered portion, and the upper tapered portion is offset the lower tapered portion.
 17. The container of claim 13, wherein the food tray is configured to withstand a baking or cooking process at a range of ovenable temperatures in a range of recommended baking or cooking times.
 18. The container of claim 17, wherein the range of ovenable temperatures is 300° F. to 600° F.
 19. The container of claim 17, wherein the range of recommended baking or cooking times is 15 minutes to 5 hours.
 20. The container of claim 13, wherein the recess has a width in a range of 0.040 to 0.060 inches. 